Abstract

An analysis is presented for the backscattering from a roughened sphere. Particular emphasis is given to the wavelength-dependence of the backscattering cross section. We examine in detail the varying contributions to the radiation from annular regions of the sphere as a function of the rms roughness, σ, the surface correlation length, l_c, and the wavelength, λ. By examining the luminosity of these different portions of the sphere, we find that the surface roughness tends to provide appreciable backscattering from extended regions, thereby enabling one, at least conceptually, to remotely sense object shape. On the other hand, when the ratio σ/λ is small, only the well-known specular point leads to a substantial return. In analyzing the effect of increasing surface roughness on the backscatter, we also include the notion of shadowing, which becomes important above angles of approximately Φ = tan^-1l_c/σ.

© 1990 Optical Society of America